Mountain Bike Reviews Forum banner

Review: New "Solarstorm" 2S2P 8.4V "water resistant" 4 x 18650 battery case for bicyc

115K views 410 replies 60 participants last post by  mzapata1975 
#1 · (Edited)
Review: New "Solarstorm" 2S2P 8.4V "water resistant" 4 x 18650 battery case for bicyc

Finaly manufacturer of an old 2S2P battery case made a new improved one. The old one has virtualy gone out of stock at any known seller. I've got cases from two sources (Gearbest and Kaidomain) to see if there is any variance in the production. The case is mostly used to power bicycle lights with 4 Li-ion 18650 cells of your choice. Cells are set in a 2S2P configuration which gives double capacity and 8.4V or can be used in 2S1P configuration.

The information about it has been already published in the thread here but I would like to make it in one place since I've done some important measurments.

Pictures of the case:







Electrical description:



There is an arror in description under nr. 6 - it should write: "USB maximum current ...... 2000mA"

The cells has to be inserted differently than with old case. It is marked in the case but I would advise you should mark it also on the cover near the springs so you can check again when you are closing the case. The cover is rectangular so it can't be placed in wrong direction. Cells are placed diagonaly so the cover can be inserted in any of two directions.



In the bottom of the case there are two connectors to connect cells in series.



What I don't like is that the all four are not cross connected like in the old case. That way electricaly looks like we would have two 8.4V cells in parallel. If they would be cross connected we would have like one big cell same as almost all welded 2S2P battery packs. What I'm also missing is the connection from the bottom to the protection circuit in order to check the voltage of each cell in series.

Protection Circuit

Big improvement in this new case is the protection circuit. I've made few measurments on different features.

Overcharging cut off kicks in somewhere at 8.46V in both cases. So if the charger fails to stop charging protection circuit would cut it off. Big and the most important improvement over the old case. Next feature is overdischarge protection. There I've got mixed result depending on the case and the current. It was funny when running at low current ovedischarge protection kicked in quite late, to late for my opinion. I've got 4.60V at virtual no load (0.02A just light connected), but 5.05V at 2.4A load (regulated single XM-L driver). So the cut off would depend on the load and the light you are using. To me this is not that important as I've found 4 different 2 led lights starts dimming much before and you'll notice low voltage anyway. Underdischarge protection restores at 6.0V at both samples if the cells can regenerate to that extend.

There are three status lights which shows the status (ie. voltage) of the pack when you push on the On/Off switch near to them.

Frame sourceGearbestKaidomain
3 status leds8.4V8.4V
2 status leds7.45V7.60V
1 status led6.95V7.10V
1 status led flashing6.45V6.60V

So the difference is constant 0.15V - not that much and probably due to resistors tolerance on the PCB. Showing status leds takes the 0.5mA current out of the batteries.




Standby current

Or in another words self discharging. By description it should be 10 microA. No way near the truth or it is just a mistake in the description: micro instead of mili. I've got 8.6mA with the Gearbest sample and 8.5mA with the Kaidomain sample. This can be of concern if you are leaving the pack uncharged for longer period. If we take the lowest 18650 cells capacity of 2200mAh we would use nowadays (ie. 4400mAh for the pack) it woud get drained in a 4400/8.5 = 518h or 21 days. This is bad news so be aware and take the cells out of the box when not used or recharged for more than 3 weeks or with higher capacities for a month.

Latest test shows this parasitic drain stays active all the time even when the cells drain below overdischarge point. This is dissapointing to me. Yet I can recall the similar issue with Magicshine ALU pack with led display showing the status. They might clone their circuit, though :(

USB Output

Some would find it usable and some not. For the ones who would like to connet GPS/Phone in paralell to the light this would be usable. For the others this might be just unneded appendix. Anyway I've measure output voltage and got it 5.02V. It could charged my phone so it delivers at least 1A.

Pros:

  • protection circuit with overcharge and overdischarge protection
  • showing the stage of the pack
  • smaller and lighter than before
  • wide strap to fasten it to the bicycle frame
  • USB output (for some people only)
  • interchangable battery cells
  • cells can be charged outside of the case - balancing possibilities

Cons:

  • no cross connections in the bottom of the case
  • no connection from the bottom to the PCB
  • only Solarstorm type of connector (compatible somewhat with Magicshine, though)
  • no or bad water resistance (would need bit thicker o-ring)
  • no watter tight cover for USB connector
  • high standby current of 8.5mA




Overall impression


It is nice case and unfortunately the only one of that type I know. This version is more usable than previos one and much more safe to use, just like welded battery packs we are mostly see in the bicycle light sets. To bad it doesn't have cross connections at the bottom and wire to the PCB. In this regard welded battery packs are still better. On the other hand you can charge cells individualy from time to time to get balanced, but you need additional individual (multibay) charger. To bad the case is not very water resistant. Using some silicone grease would help to solve that somewhat. Big issue that I see now is high standby current of 8.5mA. Be aware and take cells out of the case when not used for a longer period ie. more than 3-4 weeks.

To test in the future:
Would need to test also short protection and overcurrent protection. Actualy I would leave short test as a last thing to do and I don't have any high current drain device prepared right now. Would need to think of something....

Max. USB current is also to be tested in the future.




EDIT:

Protection circuit pictures








Any comments and suggestions to enhance the review are welcome.
 
See less See more
13
#52 ·
Anybody know either where to find a nice water-resistant "bag" for this case? Got a pretty good one along with a "6600mAh" TrustFire last year, has like this non-woven, hexagonal patterned siliconey thing going on which I've never seen any other place. Problem with that bag though, just one thin strap off center.

Product Cap Black Grey Coquelicot


As previously mentioned, this slick hard case is not deemed entirely waterproof, and the included velcro strap, while nice and wide, offers little in the way of traction or protection.

Thanks for any helpful links.
 
#53 ·
Hi Ledoman and others

I received the battery case as a gift together with the Yinding from Gearbest.

As far as I understand, I have 2 options to charge the batteries:
- connect a classical wall charger (I have about 4 at home, always included with the light units I bought) and connect it as if it was a soldered battery pack
- charge separately the batteries using Xtar, Nitecore or any other 18650 charger.

And the best would be to combine both methods: charge every now and then the batteries separately otherwise charge them together.

Following that advice, I just ordered a XTar VP2 charger (25$ at GB).

Now only one thing missing, batteries :-D

As the box is protected, I think I better buy unprotected cells.
A preference here? Wasn't there a model to avoid because of higher voltage?

Thx!
 
#59 ·
Yeah well if you choose their free shipping option with ChinaPost is says like 30-60 days. :eekster: I paid the extra $5 for two week expedited, the promo code made up for the difference. Dunno what the options are shipping to Europe.

Ordered bunch of stuff from both KD and GB over past coupla weeks and not so much as a tracking number yet, so... Eh. I can wait til Spring. ;)
 
#60 ·
According to Ledoman review on first page, this box implements highly unusual connection scheme: serial connection of two cells first, then parallel connection of resilting pairs in parallel, with no sensing wire from the middle point(s).

It is fundamentally impossible for protection PCB to determine actual voltage of particular cell in that design - it just assumes that voltage is supposed to be equal between two cells in each pair...
 
#64 ·
With Panasonic you can't miss. Of course it is good to mark cells and check them ocasionaly to see how they differ. As suggested before I would combine both charging methods when use the pack frequently.

Because parasitic drain DON'T FORGET to disconnect/take out the cells when not used for longer time. With Panasonic 3400 this period is about 1 month.

Regarding chargers, I'm working on 8.4V 2A Li-Ion charger to have much shorter charging times. Currently I'm searching for a good manufacturer. Then GB will take over if they decided to do so. Should make a new thread to see what is the demand..... Is there on this site soem voting tool or similar?
 
#70 ·
Some More Voltage Tests

Good day!

I ran some more voltage tests on my quest to find out the better box for my most power hungry light. This time I made it so that the test setting can be easily reproduced if needed.

Three battery packs were used. A random four cell stock pack, an old model Solarstorm box and a modified new model Solarstorm box which power wires are connected straight to battery terminal lines to bypass the protection circuit in hopes of better performance.

Protected 2600 mAh Sanyo UR18650ZY's were used in the boxes. The random pack has never been torn apart, but it has around half the capacity of a Sanyo set. All the batteries were fully charged prior to the test. Around 3.4 ampere load was provided with an XM-L2 Solarstorm XT40 light.

The resting voltage was measured prior to and two minutes after the load. The supply voltage was measured around every 30 seconds for a duration of three minutes.

RND: Random pack voltage (V)
Old: Old box voltage (V)
New: Modified new box voltage (V)

Time RND Old New

0:00 8.43 8.39 8.40 - unloaded

0:30 7.34 7.20 7.17
1:00 7.24 7.13 7.12
1:30 7.20 7.09 7.08
2:00 7.16 7.07 7.06
2:30 7.13 7.06 7.04
3:00 7.10 7.03 7.02

5:00 8.16 8.30 8.32 - unloaded

Here I swapped the batteries within the boxes to see that the differences were not due to different set of batteries. Random pack was untouched.

Time RND Old New

0:00 8.18 8.32 8.31 - unloaded

0:30 7.16 7.19 7.14
1:00 7.11 7.13 7.09
1:30 7.08 7.10 7.06
2:00 7.05 7.07 7.03
2:30 7.04 7.04 7.01
3:00 7.02 7.01 6.99

5:00 8.11 8.24 8.23 - unloaded

It still seems the new box is slightly inferior to the old box in terms of voltage drop despite bypassed protection circuit, but only marginally. One could separate the USB and main supplies all the way from the circuit board, or just plain remove the USB supply, to get rid of the flimsy part of wiring for some more gains, but it's hard to tell if it's worth it. The random pack does surprisingly well.

Good rides!

JK
 
#71 ·
Ok, qqick&dirty..
nothing to add to post no 1 so far

Some vendors proclaim this item as waterproof, others as water resistent:

Do not use in the water!
IPX4: 100% dustproof, resistant against splashing water

My test, 8 h under water ;), added stress: 70,05 mm extra long (and extra thick) Samsungs


The LEDs were still illuminating


A little water ran into, nevertheless a good result compared to many other "waterproof" stuff


All in all, in my eyes absolutly recommandable!

My Defys are happy, too!
Perhaps the cable is a bit too long for biking, the wire may be too thin for high current use.
So keep it with 3A max. heads only.

In comparison a "100% Waterproof bottle" from wallbuys:

Completely filled with water after 2h
Corrosion on poles and balancing connector

Complete gallery on Abload.de
 
#74 ·
Damn, still waiting on parts to arrive. I have a couple of boxes on route (well hopefully they are on route), will see if they are the non USB version or not when/if they arrive.

Also, I am still waiting for part two of two of my battery order. I got the charger and one pair of batteries, but still need to get the other three pair ordered.

Getting to be annoying.
 
#76 ·
4 x 18650 case arrived

Well I finally got the two boxes I ordered. Like others, my order was filled with the newer style box that has the USB connection as well. What are folks doing with this. Is is safe to cut it off and seal it off with tape?

I loaded up both cases with the 18650 Keep Power 3400mah batteries. As noted the case has markings to show how the batteries need to be loaded and is rectangular so the lid can only go on as it should. A ran my XT40 and also my Dinotte Dual Quad 1200+ (bonus the battery case works perfectly on my Dinotte lights) with two large fans providing the cooling, so all good there. I periodically checked the battery levels by hitting the button on the case. When it was down to 1 light of 3, I turned off the light and took out the batteries.

Now for the noob question. When I put the batteries back in my Soshine H4 charger I noticed that 2 of the 4 cells were discharged down to 15% - 20% range while the other two where still almost at full charge. Does that seem normal. Based on how the battery case is built, should all 4 batteries be discharging at an equal rate, or first discharge the first pair, then move onto the second pair?

Will try again this evening and take better notice of the battery level off of the XT40 vs the Dinotte.
 
#77 ·
Now for the noob question. When I put the batteries back in my Soshine H4 charger I noticed that 2 of the 4 cells were discharged down to 15% - 20% range while the other two where still almost at full charge. Does that seem normal. Based on how the battery case is built, should all 4 batteries be discharging at an equal rate, or first discharge the first pair, then move onto the second pair?
If the cells are identical and charged to the same level, they should discharge at equal rate. Keep in mind this box is unable to monitor them properly (essentially, "protection circuit" is a joke), but as long as you're using protected cells - no problem...
 
#78 ·
Something sounds strange, as if two of the cells are not connected in parallel to the other two. Why don't you try putting two cells on one side of the box and see if the light works. Then move the same two cells to the other side of the case and see if it works again. IF one side is not working than you have a connection issue somewhere.

-Garry
 
#81 ·
Thanks for the feedback and ideas. Will check out tonight. All cells are new KeepPower 18650 3400mah. I picked up 4 pairs. 1 arrived with charger, three shipped later and had a different sticker on the package indicating production date.

Is the idea is that two batteries are connected together (parallel) to get the 7.4v - 8.4v, then the second set of batteries in series to provide additional capacity 3400mah x 2 = 6800mah.
 
#84 ·
> I loaded up both cases with the 18650 Keep Power 3400mah batteries.

Did you check the voltage on the batteries before putting them into the battery box?
Or put them all in the external charger to see they were fully charged?
If they weren't all charged to the same level at the start, that would explain what you saw.

I wouldn't expect cells right out of the shipping box to be consistently fully charged.

Just checking
 
#85 ·
> I loaded up both cases with the 18650 Keep Power 3400mah batteries.

Did you check the voltage on the batteries before putting them into the battery box?
Or put them all in the external charger to see they were fully charged?
If they weren't all charged to the same level at the start, that would explain what you saw.

I wouldn't expect cells right out of the shipping box to be consistently fully charged.

Just checking
All the batteries were fully charged on the SoShine H4 charger. All showed 100% (full) capacity.

It might be a limitation of the H4 charger but it shows only the following information per cell. 1) % full, 2) time on charger, 3) what appears the change in MAH from when it was put on the charger to the current.

So if you had a battery rated at 3400mah that was 50% full when starting to charge, the largest mah number you would see is 50% of 3400 or 1700MAH. I guess you simply have to hope the batteries are capable of the full mah capacity.

I will double check when I get home but don't think the voltage is able to be shown.
Edit did a search and found an online picture. It does appear that is shows the voltage.

Soshine H4 1.5" LCD 4-Slot Universal Charger for Li-ion / LiFePO4 / 26650 / 18650 / AA / AAA - Black - Free Shipping - DealExtreme
 
#87 ·
Ok, just finished a couple of hours of testing. All cells were 100% charged all showing 4.2v. All cells are KeepPower 3400mah protected cells.

I did try both boxes with running just two cells. It worked just fine for both series. Both boxes worked with just two cells.

After 2.5 hours of running the XT40 light on high, with a fan to keep things cool, I took the batteries out of the case and loaded back into the H4 charger. The charger showed the cells with the following percentage remaining: 12%, 65%, 59%, 25%.

I am just running the second light and battery set to see what comes. I will be more careful in taking out the batteries. I will take them out in pairs that are tied together in series (see I can learn new things). I am curious to see if one set is getting drained more than the other, or one of the batters in each series.

Any ideas on what is happening?
 
#91 ·
I actually have the same Battery Box and made the same epxerience. I have Panasonic NCR 16850B as batteries. The voltage charged in the Nitecore D4 is the same and i also switched them through and 2 in the same position are always lower than the others. While 2 have 4,1V left, the others are at 3,95V already.
 
#92 · (Edited)
Finally, got my box today. As expected, in its default state it's not really usable - but it's possible to fix almost all problems relatively easy.

My box have PCB different than in first ledoman message: S112A1 instead of S112A. Arrangement of electronic components is totally different, but schematic is almost identical. Later I'll take some pictures of my version.

Good news: I was right about the protection IC used. Vimicro VA7022 is indeed pretty standard dual-cell protection chip. Found Chinese datasheet here:
VA7022_DS_1.2_CH-ÖÐÐÇ΢˫½Ú﮵ç³Ø±£»¤Ð¾Æ¬_°Ù¶ÈÎÄ¿â

Text Line Parallel Display device Rectangle


The SolarStorm has used "quick & dirty" trick to fool it, providing fake middle point "connection" signal to pin 4 by using resistive divider (two 100k resistors R9 and R10), and it's quite easy to restore normal functionality. The main problem is a mechanical work required to provide actual wiring; now I have some ideas on how to do it, but haven't decided the best method yet.

According to datasheet, the IC is suitable to whole range of modern cells: overcharge triggering voltage is 4.350V ± 25mV, and overdischarge 2.300V ± 80mV - so, latest low-voltage Panasonics and high-voltage cells from all the other manufacturers theoretically should be useable. Haven't measured actual triggering voltages yet.

The USB part can be easily disabled without heavy modifications. 5V DC/DC converter is controlled by the same button as voltage indicator - so, cutting the PCB trace between U2 and U1 (before grounding 10k resistor) is all what you need in order to do that.

With that mod, standby current is 1.7 mA: pretty acceptable IMHO.

I'll post some pictures when final modification will be done. For now, big thanks to ledoman for excellent review, and to GJHS for assistance in getting the box!
 
#98 ·
The USB part can be easily disabled without heavy modifications...With that mod, standby current is 1.7 mA: pretty acceptable IMHO.
I do not agree.
The USB facility is too nice to forget, I wouldn't miss this option.
Shortly before the Gearbest deal I ordered this box regularly from another supplier, it was "stolen" by my daughter for her Android gadget, seems to be better than those ugly power banks..;)

Back to topic:
As mentioned before the box sucks about 8.5 mA at standby, pretty normal for a stepdown waiting and doing "nothing".

After cutting the buck supplement from supply the current reduces to less than 40 uA.

All you have to do for a happy USB supply is connecting to the switched power, so the batts can't be exhausted.
I was lasy and did mine q&d with cutting knife, fat solder tip and fat cable rest lying around ;)


Regarding the claimed voltage differences..
- The inner resistance of the cells may differ a little within the first cycles
- The inner resistance depends highly on the drain

But it won't declare such great diffs, I assume a contact prob, too.
Considerable diffs may occur when the connected lamp is only driven at high current after many cycles.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top